OVIDUCT HISTOCHEMISTRY AND SITE OF SYNTHESIS OF A 29.7-KDA JELLY COATGLYCOPROTEIN IN THE ANURAN LEPIDOBATRACHUS-LAEVIS

The oviduct of the anuran Lepidobatrachus laevis contains three morpho logical regions, each of which contains a histochemically distinct lum inal mucosa. In the pars recta, the most anterior portion of the ovidu ct, there are periodic acid-Schiff base (PAS)-positive simple glands a nd epithelia. In the pars convoluta, there are alcian blue-positive, c ombined alcian blue- and PAS-positive and PAS-positive gland types. Th e most posterior region, the pars uterina, contains alcian blue-positi ve and alcian blue-negative epithelial cells. Previous work has shown that solubilized egg jelly contains a major 29.7 kDa glycoprotein subu nit that was detected in oviduct tissue extracts from the pars convolu ta in the present study. Rabbit antisera to the 29.7 kDa egg jelly gly coprotein of L, laevis reacted with the major pars convoluta glycoprot ein and there were no immunoreactive components in the pars uterina. T he slight immunoreactivity detected at 29.0-37.0 kDa in pars recta ext racts is not believed to be the jelly molecule, based on low immunorea ctivity and subunit molecular weight measurements. We conclude that th e synthesis of the 29.7 kDa egg jelly glycoprotein is restricted to th e pars convoluta region of the oviduct.